fix(minErr): remove references to internals APIs

So that we can use minErr with angular-loader, before full angular is loaded.

This also fixes replacing the version during the build.
fix(loader): don't rely on internal APIs

This significantly increases the size of the loader:
- minified: 1031bytes -> 1509bytes (+46%)
- minified + gzip: 593bytes -> 810bytes (+36%)

I'm not entirely sold on the idea of shipping minErr with the loade. With the current state, the angular-loader behavior is completely broken - this is just a quick fix, we can revisit this change in the future.


Closes #4437
Closes #4874
fix($animate): ensure the DOM operation isn't run twice

Depending on the animations placed on ngClass, the DOM operation may
run twice causing a race condition between addClass and removeClass.
Depending on what classes are removed and added via $compile this may
cause all CSS classes to be removed accidentally from the element
being animated.

Closes #4949
fix(ngClass): ensure that ngClass only adds/removes the changed classes

ngClass works by removing all the former classes and then adding all the
new classes to the element during each watch change operation. This may
cause transition animations to never render. The ngClass directive will
now only add and remove the classes that change during each watch operation.

Closes #4960